I've been using Square for years and they charge 2.75% roughly per transaction. The fee comes out of the money the receiver is getting. The percentage has never scared me away though, money has always been transferred into my bank account in a timely manner. It's a great service but it isn't fee free so to speak.

The smartphone app to send $ is free, it is connected to your debit card. Try it for free and they send a real dollar to your account, also free. I choose to use it because it is free, I choose not get involved with(Square)swipe or manual credit card entries because they are not free. With 2.75%(+/-)per transaction you might as well stick with PP.